Rotary wire brushes



March 27, 1956 A. J. FLOHR 2,739,332

ROTARY WIRE BRUSHES Original Filed April 2, 1948 2 Sheets-Sheet l Fae. I.

FIG. 3.

7, I 10 75 75 75 Wfi an" firm/Zn ATTORNEY.

March 27, 1956 A. J. FLOHR 2,739,332

ROTARY WIRE BRUSHES Original Filed April 2, 1948 2 Sheets-Sheet 2 75 r if \NvENToR,

A 'TOF'QNEY- ROTARY WIRE BRUSHES Alfred J. Flohr, Kenmore, N. Y., assignor of two-fifths to John C. Ward, Buffalo, N. Y.

Continuation of abandoned application Serial No. 18,615, April 2, 1948. This application April 12, 1954, Serial No. 422,369

1 Claim. (Cl. 193) This application is a continuation of my application,

Serial Number 18,615, filed April 2, 1948, and now abandoned.

This invention relates to improvements in rotary wire brushes, that is to say rotating brushes having wire bristles in annular series.

Literally hundreds of specific uses in industrial operations require high speed rotary brushes of the utmost sturdiness, a requirement which can be satisfied only by brushes having wire bristles. As examples of such uses the following may be mentioned: Removing burrs on sheet metal, stampings and castings; removing weld scale; removing paint and rust; removing flash on molded rubber parts, both hard rubber and soft rubber; removing flash on various molded plastic articles;a'nd microfinishing or polishing of machined parts. According to the purpose of use for which the brush may be intended the wires of the bristles are required to be in different gauges ranging from .0095 as a minimum to .018 as a maximum.

The efficiency of the brushes for a particular purpose of use depends upon the speed of rotation and the pressure with which the brush is applied to the work. The speed of rotation ranges from the order of 3500 r. p. m. to the order of 12,000 r. p. m. Rotary wire brushes may be broadly characterized as narrow faced and wide faced. The narrow faced brushes have a peripheral width of from one-half to three-quarters of an inch and the wide faced brushes have a peripheral width from one inch to three inches. The narrow faced brushes being lighter in weight than the wider faced brushes maybe operated at a substantially greater number of revolutions per minute. As to both the narrow faced and wide faced brushes the permissible number of revolutions per minute is related to the overall diameter of the brush,

the brushes of greater diameter having a permissible rnax imum operating speed (r. p. m.) proportionately less than the brushes of less diameter. For example, and referring to the brush of the invention, a wide faced brush having a peripheral width of one and three-quarters inches and a diameter of ten inches may have a permissible maximum operating speed of 3000 r. p. m.; this speed is greater for a brush of eight inches in diameter; still greater for a brush of six inches in diameter and maximum (5000 r. p. m.) for a brush of four inches in diameter. In like manner in the case of a narrow faced brush the permissible maximum speed ranges from 5500 r. p. m. for a brush eight inches in diameter to 12,000 r. p. m. for a brush four inches in diameter.

As examples of ideal operating speeds to insure the effectiveness of the work to be done with wire brushes: with a wire brush of 4 inches diameter the ideal speed is of the order of 12,000 r. p. m. which results in a peripheral speed of 2.3 miles per minute; with a wire brush of 6 inches diameter the ideal speed is of the order of 7,000 r. p. m. which results in a peripheral speed of 2 plus miles per minute; with a wire brush of 8 inches diameter the ideal speed is of the order of 5500 r. p. m. which results in nited States Patent a peripheral speed of 2 plus miles per minute. It will be manifest from the. peripheral travel of the brush in a minuteiof rotation .at the speeds above referred to as examples enormous centrifugal forces are developed throughout the entire range of sizes. The brushes of the invention have uniformly been'safely, successfully and endurably used in many varied industrial applications at the ideal operating speeds. No prior wire brush known in industrial use is capable of safe or enduring operations at these speeds, their operations being of necessity limited to speeds substantially below the speeds enumerated whereby their safety and efiiciency of operation are very much below the safety and efiiciency of brushes embodying the features of the invention.

The mechanism for the operation of the brush includes a suitable motor which may be an electric motor or a fluid motor and is of two types, namely portable and stationary. In the case of the portable type the operator holds the mechanism in his hands and applies the brush tothe Work with appropriate pressure. In the case of the stationary type the operator holds the work in his hands and applies the work to the brush with appropriate pressure. In either case from the operators standpoint the work is arduous and fatiguing.

The brushes in industrial use prior to my invention have been made by diiferent'rnanufacturers and have common structural characteristics. These prior brushes embody metal side plates which are intended with clamping effect to hold the bristles between them, the bristles of course projecting radially to a suitable extent beyond the side plates. In assembly the bristles,arranged as a ring, are

placed concentrically betweenthe side plates and these are subjected to a pressure averaging three tons p. s. i. in order securely to clamp the bristles. The side plates are thereupon connected by rivets or welding or by parts thereof which have a press fit.

The prior brushes, as generally described in the preceding paragraph, have a number 'of serious objections. Theseare: (1) The high pressure applied to the metal side plates in the assembly operation will cause the shearing of some of the bristles. As soon as'the brush is put into use the sheared bristles will be dislodged by centrifugal force under the high operating speeds required. The flying bristles are a physical hazard to the operator and other workmenwho may be standing sufficiently near. Another disadvantageous result is that the dislodgement of the sheared bristles impairs the clamping effect intended to be exercised by the metal side plates. A third disadvantage is that the dislodgement of the sheared bristles tendsto unbalance the brush with the result that in the application ofthe brush to the work there is a periodic pounding effect which causes fatigue to the operator and which involves undue wear of the bristles by which it is produced. (2) The pressure of the bristles against the work is in the radial direction. The radial inward thrust of the bristles is transmitted to the nonyielding metal base of the channel in which the bristles are fitted with the result of an added factor contributing to the fatigue of the'operator. (3)- The bristles should normally be as closely associated with one another as is possible. For this close association reliance is bad solely upon the resilience of the bristles. Under the pressure with which the brush is applied to the work the bristles are spread to a sensible extent. The peripheral edges of the: side plates form .hinge'points, so to speak, about which the bristles are bent in connection with their spreading under pressurel The repeated bending of the bristles about these hinge points produces unduly rapid fatigue of the bristles with the result that after a period of use many of the bristles'fail to spring back to their normal positions, the efliciency of the brush thereby being greatly impaired and its period of useful lifegreatly shortened- In the case of bristles of heavier gauge, viz., .014 inch and upwards, there, is also a marked tendency for the bristles to break with a resultant physical hazard to the workmen and further impairment of the efficiency of the brush and reduction of its useful life.

The invention is addressed tocthe foregoing problems.

It has for one of its objects .to provide a brush of this character which is so constructedas to eitectually retain the resilient wire bristles together and intactand against breaking off, and to provide a shock-absorbing cushion for the brush as a whole, thereby to increase its life to a maximum, constantly to tend to restore the bristles to their normal contracted position when the brush is removed from contact with the work being operatedupon and greatly to reduce the physical fatigue of the operator.

Another object of the invention is to provide a safe and etlicient wire brush wherein the bristles are enshrouded and confined between vulcanized rubber or plastic side walls in a manner positively to anchor the bristles in place to eliminate the hazard of their breaking loose from the brush during operation and injuring the operator or those in his vicinity.

A further object is to provide a resiliently-backed wire brush which is so designed as to eliminate bristle fatigue and so self-contained as to absorb shocks. and eliminate excessive vibration incident to the operationof the brush, and-thereby materially increase the life of the brush a well as the machine to which it is connected.

A still further object is to provide a rotary wire brush in which bristles of substantially smaller diameters may be used than is possible with the wire brushes of comparable size heretofore used in industrial operations, the decrease in the diameter of the bristles enabling a greater number of bristles to be provided with a resultant saving of time in the particular operation for which the brush may be used and a more thorough cleaning job in that the finer wires will have better penetration in the cracks and crevices than the coarser wires. For example, in the case of a wire brush of known construction having a diameter of 6 inches and intended for use in the cleaning of the scale left by welding operations, bristles of maximum diameter (viz. .016 to .018) are required, whereas a brush in accordance with the invention and intended for the same use even when having a greater diameter, for example, a diameter of 8 inches, may be provided with bristles of smaller diameter, namely .014. The use of bristles of smaller diameter than heretofore possible enables an increase in the number of bristles up to per cent and the operating time, according to the particular use to which the brush may be put, is cut from per cent to 50 per cent with a more thorough cleaning job.

With the above objects in view the invention, generally speaking, is characterized by the arrangement of the. bristles in an annular series in relation to a retaining ring about which the bristles are bent at points between their ends to project in a general radial direction and the provision of a body element of resilient rubber having a solid resilient hub portion to cushion the thrust of the retaining ring when pressure is applied to the bristles in the use of the brush, resilient circular side Wall portions normally projecting in substantially parallel planes from the hub portion and a zone of rubber concentric to the hub portion and in which the retaining ring and the parts of the bristles located between the side portions are embedded, the rubber of'the embedding zone resiliently con necting the side portions and the embedding zone being provided by the flow of rubber between the side portions and through the interstices among the bristles in the course of the vulcanizing operation which produces the resilient hub portions and theresilient side portions. The relation of the'bristles and of the bristle retaining ring to the cushioning hub portion and the rubber of the embedding zone maybe epitomized .as a floating relation. When pressure is applied. to the bristles during the use of the brush the bristles tend tospread and the side por- 4 tions have yielding movements in laterally outward directions, the yielding of the side portions being resisted by the rubber of the embedding zone which, as its tension is thereby increased, acts with even greater holding strength on the bristles. Since the side portions yield throughout their extent of projection beyond the cushioning hub portion the bristles as they are spread laterally, consequent to the pressure applied to them during the operation of the brush, do not bend about any fixed hinge points or fulcra as they do in the known constructions. it will be noted the inherent resiliency of the bristles is not relied upon to return them to their normal positions when the pressure upon the brush is relieved, the return of the bristles to their normal positions being effected by the resilient side portions of the body element which, when the pressure upon the bristles is relieved, resume their normal substantially parallel relation by reason of their inherent resiliency and the pull exerted by the resilient rubber of the embedding zone. For these reasons the causes of unduly rapid fatigue of the bristles in the known constructions are eliminated and, as compared with the known constructions, the useful life of the brush is greatly prolonged.

In the drawings:

Figure l is a perspective view of a rotary wire brush constructed in accordance with my invention.

Figure 2 is an enlarged cross section taken on line 2-2 of Figure 1.

Figure 3 is a fragmentary longitudinal section showing the manner in which the brush is made in a mold.

Figure 4 .is a face view, partly broken away, of a modified form of the invention.

Figure 5 is a cross section taken on the line 5--5 of Figure 4.

Referring to the embodiment of the invention shown is Figures 1 to 3 inclusive:

The brush 11 of the invention is mounted upon a rotating shaft 10. It includes a resilient rubberbody element having a solid annular hub portion 12 and annular side portions or shields .13 normally projecting in substantially parallel planes from the hub portion and providing an annular channel having the hub portion 12 as its base. It also includes resilient wire bristles secured in annular series in the channel, extending radially from the hub portion and projecting for a suitable extent beyond the sidewall portions 13. The bristles are arranged according'to known practice, that is to say they are bent about a metal retaining ring 15, being folded at a central point about the ring into an appropriate V shape and provided in any appropriate number of layers, the folded or bow portions of which are concentric to the circular cross section of the ring 15. The bow portions of the folded bristles, as a series, rest and react against the annular surface of the hub portion 12 which, due to its resilience, provides a cushion to resist the radial inward thrust of the bristles when the brush is applied with pressure to the work and restores the bristles to their normal radial positions when the pressure is relieved. The side portions or shields 13 are connected by an integral body 'of resilient rubber which completely encases the bristles through an extent from the ring 15 to the peripheries of the side portions 13. This connecting body of rubber yieldably anchors the bristles and the ring 15 in the channel provided by the side portions Band the hub portion 12 and also augments the side portions in their resistance to the lateral spread of the bristles under the pressure of the brush against the work and in the restoration of the bristles to their normal closely associated relation. The connecting body of rubher which extends between the side portions 13 constitutes a zone in which the bristles are embedded and the relation of the bristles and the ring 15 to the resilient hub portion and to theembedding zone may be epitomized as afioating relation.

The novel andadvantageous physical and structural characteristics of the brush of the invention are resultant from its mode of manufacture. In general the rubber element with its solid hub portion 12 and side portions 13 and the integral body of resilient rubber which connects the side portions 13 and completely encases the bristles are produced by a molding and partial vulcanizing operation. In this operation'two similar discs of unvulcanized rubber are formed with alined central openings and with annular central portions which, when united by vulcanization, provide the solid hub portion 12. These rubber discs are also shaped to provide the spaced side portions 13. The mold consists of companion halves 17 and 18 shaped internally to produce the external configurations of the resilient rubber element. The companion mold halves have alined central bosses which project from their inner faces into the central openings of the discs of unvulcanized rubber. These discs are fitted respectively in the mold halves with the bristles and ring 15 placed between, the bow portions of the bristles adjoining the central portions of the disc which provide the solid hub portions 12. The brush is produced by the standard process of vulcanization which involves the application of heat and pressure transmitted by the companion mold halves to the rubber discs but it is not carried out to the point where the rubber element becomes brittle. The finished product is always resilient. In the vulcanizing operation the central portions of the rubber discs are united to provide the solid hub portion 12. The fluid condition of the parts of the rubber discs which provide the spaced side portions 13 result in the flow of some of the rubber of these parts transversely, that is to say through all of the interstices among the bristles whereby the ultimate side portions 13 are connected by an integral body of resilient rubber which completely encases the bristles through an extent from the ring 15 to the peripheries of the side portions 13. A predetermined amount of rubber is used to make a givensized brush and it is preferred that the outer portion of the mold 17, 18 be shaped to provide inwardly-facing annular shoulders 20 in order to seal off the spread or flow of the rubber beyond that point and yet allow the inward flow or displacement of the rubber transversely of the mold or in a direction between the bristles. It will be noted that the exposed or outer ends of the bristles, during the molding process, are preferably slightly tapered or converged by shaping the mold, as indicated at 21. This results in compressing the bristles and resisting the flow of the rubber to those ends and yet permits the proper venting of the mold through the bristles and thence outwardly through the peripheral portion 19 of the mold cavity.

As a result of the vulcanizing operation described the brush of the invention is characterized by a central solid resilient hub portion which provides a cushion to resist the inward thrust of the bristles under the pressure with which the brush is applied to the work, by spaced inherently resilient side portions concentric with the hub portion and which with the hub portion provide an annular channel to receive the bristles and the bristle mounting ring, and by an annular zone of resilient rubber which extends between and connects the side portions, fills the interstices among the bristles and encases the bristles and the mounting ring through an extent between the hub portion and the peripheries of the side portions, thereby securely to anchor the bristles in the channel while permitting displacement of the bristles under the pressure with which the brush is applied to the work both radially and laterally. The lateral displacement of the bristles results in a widening or spreading of the peripheries of the brush and is accomplished without the sharp bending of the bristles about a fixed point.

The annular zone of resilient rubber bonds the bristles, so to speak, to the resilient hub portion 12 with the bow portions of the bristles as mounted upon the ring 15 in adjoining relation to the channel base provided by the hub portion 12. The side portions 13 constitute lateral shock absorbing shieldsfor the bristles. The widening or spreading of the periphery of the brush under the pressure with which the brush is applied to the work is permitted, yet resisted, by the side portions 13 and the zone of resilient rubber which connects the side portions and encases the bristles. When the pressure of the brush upon the work is relieved the side portions 13, by their inherent resilience and aided by the zone of resilient rubber connecting them return to their normal planes and thereby return the bristles to their normal positions.

The shaft 10 is preferably formed with a reduced extension which provides an annular shoulder, the reduced terminal extension having a close fit in the central opening of the hub portion 12. The brush is flexible and resilient throughout its radial extent and is positively centered upon the shaft 10 in a position normal to its axis by hub plates 16 which are shaped to conform to the external outline of the brush, one of the hub plates bearing against the shoulder of the shaft 10 and the other receiving the thrust of a securing nut which is tightened sufiiciently to cause the brush to rotate with the shaft. The hub plates 16 are of suitably less diameter than the brush whereby the brush side portions 13 project for a suitable distance beyond the hub plates and are thereby free to yield laterally under the pressure with which the brush is applied to the work. The degree of lateral yielding of the side portions 13 may be varied by appropriate selection of the-diameters of the plates 16, such variation depending upon the particular type of work for which the brush may be designed. It will be apparent that side portions 13 which may project to a greater extent beyond the plate 16 will have a greater degree of lateral yield than side portions 13 which may project to a less extent.

In the modified embodiment shown in Figures 4 and 5 instead of the metal ring 15 above described I employ a flat rubber ring 22 having openings to enable the mounting of the bristles in clusters of substantially triangular outline, the bristles of each cluster being inserted through an opening and being bent upon themselves at a central point. In the vulcanizing operation the ring with the bristles assembled is placed between the parts of the rubber disc which provide the hub portion and upon the completion of the vulcanizing operation the ring becomes an integrated part of the hub portion which has the resilient and cushioning properties previously described. In the vulcanizing operation the rubber of the discs as it becomes fluid flows through the openings in the ring 22 and fills the interstices among the bristles, a percentage of the rubber of the portions of the discs which provide the lateral shields 13 flowing through the interstices among the bristles and resiliently connecting the shields to one another, all in the manner previously described. As in the embodiment described the central resilient hub and the resilient side portions provide a channel to accommodate the bristles, the hub has the same cushioning properties in connection with the radial pressure upon the bristles incident to the pressure of the brush against the Work and the shields 13 have the same properties in connection with the spreading of the bristles as the shields of the preferred embodiment. Wire brushes as heretofore used for industrial work have two forms, viz., where the bristles project to the same extent from the hub, this being the form shown herein, and where the bristles in the transverse dimension of the brush have progressively decreasing projection from the hub with the result that the brush is of frusto-conical outline, sometimes referred to as cupshaped. The brush of the invention is susceptible of manufacture in either form.

I claim:

A rotary wire brush comprising a resilient rubber element composed of a solid resilient hub portion and 7 integral resilient side disc portions normally projecting in substantially parallel planes from the hub portion, the hub portion and the side portions providing an annular channel, an annular series of wire bristles arranged within the channel and projecting beyond the side portions, a mounting ring for the bristles normally concentric to the hub portion, located adjacent the base of the channel and about which the bristles are bent at points between their ends and from which they project radially, the rubber element including an annular zone of resilient rubber in which the retaining ring and parts of the bristles Within the channel are embedded, the embedding zone being concentric to the hub portion and the rubber thereof connecting the side portions and extending through the interstices among the bristles, the hub portion of the element providing a cushion against the inward thrust of the bristles under the pressure with which the brush is applied to the work and the side portions providing resilient shields, the bristles and the mounting ring during the application and release of the working pressure of the brush having a floating relation relatively to the hub portion and the embedding zone, the side portions being laterally yieldable in outward directions to permit spreading of the bristles under the pressure with which the brush is applied to' the work and to provide lateral shock absorbing shields for the bristles, and metal plates provided at the sides of the element for mounting the brush in a centered relation upon an operating shaft, the side portions projecting for a suitable extent beyond the plates and having their yielding action limited to the extent of their projection beyond the cushioning hub portion.

References Cited in the file of this patent UNITED STATES PATENTS 367,591 Bringold Aug. 2, 1887 376,800, Frisbie Jan. 24, 1888 587,048 Topp July 27, 1897 863,790 Dixon Aug. 20, 1907 1,713,027 Cleaves May 14, 1929 2,146,284 Churchill Feb. 7, 1939 2,172,433

Churchill Sept. 12, 1939 

